2 * Copyright (C) 2014 John Crispin <blogic@openwrt.org>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU Lesser General Public License version 2.1
6 * as published by the Free Software Foundation
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
18 #include <sys/sysmacros.h>
20 #include "libfstools.h"
23 find_overlay_mount(char *overlay)
25 FILE *fp = fopen("/proc/mounts", "r");
26 static char line[256];
32 while (ret && fgets(line, sizeof(line), fp))
33 if (!strncmp(line, overlay, strlen(overlay)))
42 * Find path of a device mounted to the given point.
47 FILE *fp = fopen("/proc/mounts", "r");
48 static char line[256];
54 while (fgets(line, sizeof(line), fp)) {
55 char *s, *t = strstr(line, " ");
82 * Match filesystem type against a bunch of valid types
84 * jffs2reset may ask if the filesystem type is actually ready for use
85 * with overlayfs before wiping it...
87 static int fs_rootfs_only(char *fstype)
89 if (strncmp(fstype, "ext4", 4) &&
90 strncmp(fstype, "f2fs", 4) &&
91 strncmp(fstype, "jffs2", 5) &&
92 strncmp(fstype, "ubifs", 5)) {
93 ULOG_ERR("block is mounted with wrong fs\n");
100 * Check if a given device is mounted and return its mountpoint
103 find_mount_point(char *block, int root_only)
105 FILE *fp = fopen("/proc/self/mountinfo", "r");
106 static char line[256];
107 int len = strlen(block);
108 char *point = NULL, *pos, *tmp, *cpoint, *devname, *fstype;
111 unsigned int minor, major;
116 rstat = stat(block, &s);
118 while (fgets(line, sizeof(line), fp)) {
119 /* skip first two columns */
120 pos = strchr(line, ' ');
124 pos = strchr(pos + 1, ' ');
128 /* extract block device major:minor */
130 pos = strchr(pos, ':');
138 pos = strchr(pos, ' ');
145 /* skip another column */
146 pos = strchr(pos + 1, ' ');
152 pos = strchr(pos, ' ');
159 /* skip another two columns */
160 pos = strchr(pos + 1, ' ');
164 pos = strchr(pos + 1, ' ');
170 pos = strchr(pos, ' ');
177 /* get device name */
179 pos = strchr(pos, ' ');
186 /* if device name matches */
187 if (!strncmp(block, devname, len)) {
188 if (root_only && fs_rootfs_only(fstype))
191 /* found, return mountpoint */
192 point = strdup(cpoint);
196 /* last chance: check if major:minor of block device match */
200 if (!S_ISBLK(s.st_mode))
203 if (major == major(s.st_rdev) &&
204 minor == minor(s.st_rdev)) {
205 if (root_only && fs_rootfs_only(fstype))
208 /* found, return mountpoint */
209 point = strdup(cpoint);
220 find_filesystem(char *fs)
222 FILE *fp = fopen("/proc/filesystems", "r");
223 static char line[256];
227 ULOG_ERR("opening /proc/filesystems failed: %s\n", strerror(errno));
231 while (ret && fgets(line, sizeof(line), fp))
232 if (strstr(line, fs))